Radically curable compound, method for producing radically curable compound, radically curable composition, cured product of the same, and resist-material composition

ABSTRACT

Provided is a positive photoresist composition excellent in terms of heat resistance. A radically curable compound is represented by a general formula (1) below (where R 1 , R 2 , and R 3  each independently represent an alkyl group having 1 to 8 carbon atoms; m and n each independently represent an integer of 1 to 4; p represents an integer of 0 to 4; X, Y, and Z each independently represent an acryloyloxy group, a methacryloyloxy group, or a hydroxy group, and at least one of X, Y, and Z represents an acryloyloxy group or a methacryloyloxy group; and t represents 1 or 2).

TECHNICAL FIELD

The present invention relates to a radically curable compound thatprovides a cured product excellent in terms of heat resistance.

BACKGROUND ART

In recent years, electronic devices have undergone remarkable technicaladvances and integrated circuits having a higher density and higherperformance have been rapidly developed. In response to suchdevelopments, printed wiring boards have come to have a higher density,more highly integrated wiring, and surface-mounted components. Suchprinted wiring boards also need to have a higher accuracy and higherperformance than before. In response to such developments of integratedcircuits having a higher density and higher performance, there have beenstudies on improvements in the performance of solder resist serving as amain material of integrated circuits. Build-up boards and the likehaving fine wiring therein still have a problem in that cracking occursat the interface between solder resist and sealing resin, which isreferred to as popcorning. Thus, there has been a demand for a solderresist having higher heat resistance.

With an increase in the degree of integration of integrated circuits,nanoimprint lithography has been attracting attention as a process forultrafine patterning allowing a linewidth of 20 nm or less. Thisnanoimprint lithography is broadly divided into thermal nanoimprintlithography and photo nanoimprint lithography. The thermal nanoimprintlithography is performed in the following manner: a polymer resin isheated to a glass transition temperature or higher to be softened; amold is pressed into this resin; and the mold is released from the resinhaving cooled, so that a fine structure is transferred to the resin on asubstrate. Thus, nano-patterns can be formed at relatively low costs.The thermal nanoimprint lithography is expected to be applied in variousfields. However, the thermal nanoimprint lithography requires softeningof such a polymer resin by heating and polymer resins having a highglass transition temperature are difficult to use. Thus, the thermalnanoimprint lithography is difficult to apply to the electric andelectronic field in which higher heat resistance has been required inrecent years.

On the other hand, the photo nanoimprint lithography employsphoto-curing of a composition upon irradiation with light. The photonanoimprint lithography does not require heating of a molding materialto which a pattern is transferred during pressing. Thus, imprinting canbe achieved at room temperature. Photo-curable resins used for the photonanoimprinting are of a radical polymerization type, an ionicpolymerization type, and a hybrid of these types. Curable compositionsof any of these types can be used for nanoimprinting. However,photo-curable compositions of the radical polymerization type, of whichthere is a wide choice of viable materials, have been commonly studied.

In the cases where materials for nanoimprinting are used for protectivefilms and spacers for thin-film transistors and liquid crystal colorfilters in liquid crystal displays and for permanent films used for fineprocessing of other members for liquid crystal display apparatuses,cured products of the materials for nanoimprinting need to be excellentin terms of mechanical property, transparency, light resistance, heatresistance, or the like and, in particular, need to have very high heatresistance. Known examples of such a material that can provide curedproducts having high heat resistance are epoxy (meth)acrylate resinshaving a biphenyl skeleton (for example, refer to Patent Literature 1).However, these resins do not have the high heat resistance that has beenrequired in recent years.

CITATION LIST Patent Literature

PTL 1: Japanese Unexamined Patent Application Publication No. 9-157340

SUMMARY OF INVENTION Technical Problem

An object of the present invention is to provide a radically curablecompound that provides a cured product excellent in terms of heatresistance and another object is to provide a method for producing thecompound.

Solution to Problem

The inventors of the present invention performed thorough studies. As aresult, the inventors have found, for example, the following findings: acured product has very high heat resistance, the cured product beingobtained by curing a compound having a structure that is provided by areaction between a trifunctional phenol having a specific structure anda (meth)acrylic acid halide; and such a method allows easy production ofthe compound. Thus, the inventors have accomplished the presentinvention.

Specifically, the present invention provides a radically curablecompound represented by a general formula (1) below

(where R¹, R², and R³ each independently represent an alkyl group having1 to 8 carbon atoms; m and n each independently represent an integer of1 to 4; p represents an integer of 0 to 4; X, Y, and Z eachindependently represent an acryloyloxy group, a methacryloyloxy group,or a hydroxy group, and at least one of X, Y, and Z represents anacryloyloxy group or a methacryloyloxy group; and t represents 1 or 2).

In addition, the present invention provides a method for producing aradically curable compound, the method including causingpolycondensation between an alkyl-substituted phenol (a1) and anaromatic aldehyde (a2) having a hydroxy group on a benzene ring toprepare a polycondensate (A) represented by a general formula (3) below

(where R¹, R², and R³ each independently represent an alkyl group having1 to 8 carbon atoms; m and n each independently represent an integer of1 to 4; p represents an integer of 0 to 4; and s represents 1 or 2); and

subsequently causing a reaction between the polycondensate and a(meth)acrylic acid halide (B).

In addition, the present invention provides a radically curable compoundobtained by the above-described production method.

In addition, the present invention provides a radically curablecomposition including the above-described radically curable compound.

In addition, the present invention provides a cured product obtained bycuring the above-described radically curable composition with an activeenergy ray or heat.

In addition, according to the present invention, a resist-materialcomposition includes the above-described radically curable composition.

Advantageous Effects of Invention

A radically curable compound according to the present invention canprovide a cured product having heat resistance on a very high level.Accordingly, a radically curable compound according to the presentinvention can be used as a solder resist material and a material fornanoimprinting that are required to have high heat resistance. Aradically curable compound according to the present invention is amaterial that is photo-curable and can be used to form a shape by lightand hence can also be used for a material for a mold of the thermalnanoimprint lithography. In a case where a thermoplastic resin used asresist in the thermal nanoimprint lithography is a high-heat-resistantelectric/electronic-material engineering plastic having a glasstransition temperature (Tg) of more than 200° C. such as polyphenyleneether (PPE), this plastic is subjected to a softening treatment at atemperature of 300° C. or more. In this case, a cured product of aradically curable compound according to the present invention has veryhigh heat resistance and hence can be used as a material for the mold.

A radically curable compound according to the present invention hasbenzene rings at a high density and hence has a more rigid skeleton andthe cured product thereof has high heat resistance. In addition, becauseof the rigid skeleton, the cured product is also excellent in terms ofmechanical property (impact resistance) and has high water resistanceand particularly a high hardness. Accordingly, a radically curablecompound according to the present invention can be suitably used as, forexample, a hard-coating material for films formed of triacetylcellulose(TAC) or the like used as polarizing plates of liquid crystal displaysof televisions, video cameras, computers, cellular phones, or the like,the displays requiring high surface hardness; a hard-coating materialfor transparent protective films that protect the surfaces of variousdisplays such as liquid crystal displays, plasma displays, or organic ELdisplays; or a hard-coating material for optical lenses. In addition, aproduction method according to the present invention allows easyproduction of a radically curable compound according to the presentinvention.

BRIEF DESCRIPTION OF DRAWING

FIG. 1 is a ¹H-NMR spectrum chart of a radically curable compound (1)obtained in Example 1.

DESCRIPTION OF EMBODIMENTS

A radically curable compound according to the present invention has amolecular structure represented by a general formula (1) below

(where R¹, R², and R³ each independently represent an alkyl group having1 to 8 carbon atoms; m and n each independently represent an integer of1 to 4; p represents an integer of 0 to 4; X, Y, and Z eachindependently represent an acryloyloxy group, a methacryloyloxy group,or a hydroxy group, and at least one of X, Y, and Z represents anacryloyloxy group or a methacryloyloxy group; and t represents 1 or 2).

In the general formula (1), R¹, R², and R³ each independently representan alkyl group having 1 to 8 carbon atoms: specifically, for example, amethyl group, an ethyl group, a propyl group, an isopropyl group, an-butyl group, a t-butyl group, a pentyl group, a hexyl group, a heptylgroup, or an octyl group. Such alkyl groups allow high heat resistanceof cured products. R¹, R², and R³ preferably each represent a methylgroup among these alkyl groups because molecular motion is suppressed toallow high rigidity of the molecules; cured products have higher heatresistance; electron donation to phenolic benzene nuclei is allowed; andindustrial availability is high.

In the general formula (1)), m and n each independently represent aninteger of 1 to 4 and p represents an integer of 0 to 4. In particular,an integer of 1 to 3 is preferred because of, for example, highreactivity, ease of design of the reaction, or ease of industrialavailability of raw materials.

In the general formula (1), X, Y, and Z each independently represent anacryloyloxy group, a methacryloyloxy group, or a hydroxy group. Here, ina case where t in the general formula (1) represents 2, two Z's in themolecule may be the same or different from each other.

At least one of X, Y, and Z above represents an acryloyloxy group or amethacryloyloxy group. More preferably, X, Y, and Z each represent anacryloyloxy group or a methacryloyloxy group because the compound hashigh curability. In a case where X, Y, and Z represent an acryloyloxygroup, the radically curable compound has a high curing rate andprovides cured products having high adhesion to substrates. On the otherhand, in a case where X, Y, and Z represent a methacryloyloxy group, theradically curable compound tends not to undergo shrinkage on curing andprovides cured products having high adhesion to substrates.

In the general formula (1), t represents an integer of 1 or 2; tpreferably represents 1 because of ease of industrial availability ofraw materials or ease of design of the reaction.

In the general formula (1), X and Y are bonded preferably at parapositions with respect to the methine group that bonds three aromaticrings together because cured products having high heat resistance can beobtained. Thus, a preferred form of the radically curable compoundrepresented by the general formula (1) is a radically curable compoundrepresented by a general formula (2) below

(where R¹, R², and R³ each independently represent an alkyl group having1 to 8 carbon atoms; m and n each independently represent an integer of1 to 4; p represents an integer of 0 to 4; and X, Y, and Z eachindependently represent an acryloyloxy group, a methacryloyloxy group,or a hydroxy group, and at least one of X, Y, and Z represents anacryloyloxy group or a methacryloyloxy group).

Specifically, the radically curable compound represented by the generalformula (1) may have a molecular structure represented by any one of thefollowing structural formulae (1-1) to (1-14).

A radically curable compound according to the present invention can beeasily produced by, for example, a method including causingpolycondensation between an alkyl-substituted phenol (a1) and anaromatic aldehyde (a2) having a hydroxy group on a benzene ring toprepare a polycondensate (A) represented by a general formula (3) below

(where R¹, R², and R³ each independently represent an alkyl group having1 to 8 carbon atoms; m and n each independently represent an integer of1 to 4; p represents an integer of 0 to 4; and s represents 1 or 2); and

subsequently causing a reaction between the polycondensate and a(meth)acrylic acid halide (B). Note that, in the present invention,“(meth)acrylic acid” denotes one or both of “acrylic acid” and“methacrylic acid”.

The alkyl-substituted phenol (a1) is a compound in which a part of orall the hydrogen atoms bonded to the aromatic ring of phenol arereplaced by alkyl groups. Specific examples of such an alkyl groupinclude an alkyl group having 1 to 8 carbon atoms such as a methylgroup, an ethyl group, a propyl group, an isopropyl group, a n-butylgroup, a t-butyl group, a pentyl group, a hexyl group, a heptyl group,or an octyl group. In particular, a methyl group is preferred.

Examples of the alkyl-substituted phenol (a1) include monoalkyl phenolssuch as o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol,p-ethylphenol, p-octylphenol, p-t-butylphenol, o-cyclohexylphenol,m-cyclohexylphenol, and p-cyclohexylphenol; dialkyl phenols such as2,5-xylenol, 3,5-xylenol, 3,4-xylenol, 2,4-xylenol, and 2,6-xylenol; andtrialkyl phenols such as 2,3,5-trimethylphenol and2,3,6-trimethylphenol. Among these alkyl-substituted phenols, because ofhigh heat resistance, preferred are those in which the aromatic ring ofphenol is substituted with two alkyl groups; in particular, preferredare 2,5-xylenol and 2,6-xylenol. These alkyl-substituted phenols (a1)may be used alone or in combination of two or more thereof.

Examples of the aromatic aldehyde (a2) having a hydroxy group on abenzene ring include hydroxybenzaldehydes such as 2-hydroxybenzaldehyde,3-hydroxybenzaldehyde, and 4-hydroxybenzaldehyde; dihydroxybenzaldehydessuch as 2,4-dihydroxybenzaldehyde and 3,4-dihydroxybenzaldehyde; andalkyl-group-containing hydroxybenzaldehydes such as2-hydroxy-4-methylbenzaldehyde, 2-hydroxy-5-methylbenzaldehyde,2-hydroxy-3,5-dimethylbenzaldehyde, and4-hydroxy-3,5-dimethylbenzaldehyde. Among these aromatic aldehydes,because of ease of industrial availability and being highly balanced interms of heat resistance and alkaline solubility, preferred arehydroxybenzaldehydes; in particular, more preferred are4-hydroxybenzaldehyde and 4-hydroxy-3,5-dimethylbenzaldehyde. Thesearomatic aldehydes (a2) may be used alone or in combination of two ormore thereof.

The halide of the (meth)acrylic acid halide (B) may correspond tofluorine, chlorine, bromine, iodine, or astatine. Specific examples ofthe (meth)acrylic acid halide include (meth)acrylic acid chloride,(meth)acrylic acid bromide, and (meth)acrylic acid iodide. Among these(meth)acrylic acid halides, (meth)acrylic acid chloride is preferredbecause of high reactivity and ease of availability.

A specific example of a method for producing a radically curablecompound according to the present invention is a method that includesthe following three steps.

(Step 1)

Cause polycondensation between the alkyl-substituted phenol (a1) and thearomatic aldehyde (a2) having a hydroxy group on a benzene ring in thepresence of an acid catalyst to prepare a crude product containing thepolycondensate (A) represented by the general formula (5) or the generalformula (6) in a reaction solution.

(Step 2)

Collect from the reaction solution the polycondensate (A) prepared inthe step 1.

(Step 3)

Cause a reaction between the polycondensate (A) isolated in the step 2and the (meth)acrylic acid halide (B) in the presence of a base.

Examples of the acid catalyst used in the step 1 include acetic acid,oxalic acid, sulfuric acid, hydrochloric acid, phenolsulfonic acid,paratoluenesulfonic acid, zinc acetate, and manganese acetate. Theseacid catalysts may be used alone or in combination of two or morethereof. Of these acid catalysts, sulfuric acid and paratoluenesulfonicacid are preferred because of high activity. Note that such an acidcatalyst may be added prior to the reaction or during the reaction.

In the step 1, if necessary, the polycondensate may be prepared in thepresence of a solvent. Examples of the solvent include monoalcohols suchas methanol, ethanol, and propanol; polyols such as ethylene glycol,1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol,1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol,trimethylene glycol, diethylene glycol, polyethylene glycol, andglycerin; glycol ethers such as 2-ethoxyethanol, ethylene glycolmonomethyl ether, ethylene glycol monoethyl ether, ethylene glycolmonopropyl ether, ethylene glycol monobutyl ether, ethylene glycolmonopentyl ether, ethylene glycol dimethyl ether, ethylene glycol ethylmethyl ether, and ethylene glycol monophenyl ether; cyclic ethers suchas 1,3-dioxane, 1,4-dioxane, and tetrahydrofuran; glycol esters such asethylene glycol acetate; and ketones such as acetone, methyl ethylketone, and methyl isobutyl ketone. These solvents may be used alone orin combination of two or more thereof. Among these solvents,2-ethoxyethanol is preferred because the compound to be obtained ishighly soluble therein.

In the step 1, the reaction temperature of polycondensation between thealkyl-substituted phenol (a1) and the aromatic aldehyde (a2) having ahydroxy group on a benzene ring is, for example, 60° C. to 140° C. Thereaction time is, for example, 0.5 to 100 hours.

In the step 1, the charging ratio [(a1)/(a2)] (molar ratio) of thealkyl-substituted phenol (a1) to the aromatic aldehyde (a2) having ahydroxy group on a benzene ring is preferably in the range of 1/0.2 to1/0.5, more preferably in the range of 1/0.25 to 1/0.45 becauseunreacted alkyl-substituted phenol is easily removed, the yield of theproduct is high, and the reaction product having a high purity can beobtained.

Examples of the polycondensate (A) obtained as a result ofpolycondensation of the step 1 include compounds represented by thefollowing general formulae (3-1) to (3-10).

The reaction solution provided by the step 1 may contain, in addition tothe polycondensate (A), unreacted compounds of the (a1), the (a2), orthe like. Unwanted condensates may be generated that are not condensateshaving a structure represented by the general formula (5) or the generalformula (6). In a case where such a reaction solution is subjected to areprecipitation process with water to obtain a substance collected for areaction with the (meth)acryloyl acid halide (B), this collectedsubstance may contain, in addition to the target polycondensate (A),unreacted compounds of the (a1), the (a2), or the like or the unwantedpolycondensates in a large amount.

For this reason, from the substance collected from the reaction solutionin the step 2, the polycondensate (A) is preferably further collected tomaximize the purity of the polycondensate (A).

The purity of the polycondensate (A) that is to react with the(meth)acryloyl acid halide (B) is preferably 85% or more, morepreferably 90% or more, still more preferably 94% or more, particularlypreferably 98% or more, and most preferably 100%. The purity of thepolycondensate (A) can be determined on the basis of an area ratio in agel permeation chromatography (GPC) chart.

In the present invention, the measurement conditions of GPC are asfollows.

[GPC Measurement Conditions]

Measurement device: “HLC-8220 GPC” manufactured by Tosoh Corporation

Columns: “Shodex KF802” (8.0 mm φ×300 mm) manufactured by SHOWA DENKO K.K.

+“Shodex KF802” (8.0 mm φ×300 mm) manufactured by SHOWA DENKO K. K.

+“Shodex KF803” (8.0 mm φ×300 mm) manufactured by SHOWA DENKO K. K.

+“Shodex KF804” (8.0 mm φ×300 mm) manufactured by SHOWA DENKO K. K.

Column temperature: 40° C.

Detector: RI (differential refractometer)

Data processing: “GPC-8020 model II version 4.30” manufactured by TosohCorporation

Developing solvent: tetrahydrofuran

Flow rate: 1.0 ml/min

Sample: obtained by filtering tetrahydrofuran solution having 0.5 mass %resin solid content through microfilter

Injection amount: 0.1 ml

Standard samples: monodisperse polystyrenes below

(Standard Samples: Monodisperse Polystyrenes)

“A-500” manufactured by Tosoh Corporation

“A-2500” manufactured by Tosoh Corporation

“A-5000” manufactured by Tosoh Corporation

“F-1” manufactured by Tosoh Corporation

“F-2” manufactured by Tosoh Corporation

“F-4” manufactured by Tosoh Corporation

“F-10” manufactured by Tosoh Corporation

“F-20” manufactured by Tosoh Corporation

In the step 2, impurities such as unreacted compounds of the (a1), the(a2), or the like are separated from the polycondensate (A), so that theresultant radically curable compound according to the present inventionhas high crystallinity. Thus, a radically curable compound according tothe present invention tends to be closely packed. A radically curablecompound according to the present invention in the state of beingclosely packed is cured. As a result, the molecular motion of the curedproduct is suppressed. Thus, the glass transition temperature becomes400° C. or more and the heat resistance can be at least doubled,compared with existing cases.

The process of collecting the polycondensate (A) from the reactionsolution in the step 2 can be performed, for example, in the followingmanner. The reaction solution is added into a poor solvent (S1) in whichthe reaction product is insoluble or slightly soluble and the resultantprecipitate is separated by filtration. The precipitate is thendissolved in a solvent (S2) that can dissolve the reaction producttherein and is compatible with the poor solvent (S1). This solution isadded to the poor solvent (S1) again and the resultant precipitate isseparated by filtration. Examples of the poor solvent (S1) used hereinclude water; monoalcohols such as methanol, ethanol, and propanol;aliphatic hydrocarbons such as n-hexane, n-heptane, n-octane, andcyclohexane; and aromatic hydrocarbons such as toluene and xylene. Amongthese poor solvents (S1), water and methanol are preferred becauseremoval of the acid catalyst can also be simultaneously achievedefficiently.

On the other hand, examples of the solvent (S2) include monoalcoholssuch as methanol, ethanol, and propanol; polyols such as ethyleneglycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol,1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol,1,9-nonanediol, trimethylene glycol, diethylene glycol, polyethyleneglycol, and glycerin; glycol ethers such as 2-ethoxyethanol, ethyleneglycol monomethyl ether, ethylene glycol monoethyl ether, ethyleneglycol monopropyl ether, ethylene glycol monobutyl ether, ethyleneglycol monopentyl ether, ethylene glycol dimethyl ether, ethylene glycolethyl methyl ether, and ethylene glycol monophenyl ether; cyclic etherssuch as 1,3-dioxane and 1,4-dioxane; glycol esters such as ethyleneglycol acetate; and ketones such as acetone, methyl ethyl ketone, andmethyl isobutyl ketone. In a case where water is used as the poorsolvent (S1), the (S2) is preferably acetone. Note that, regarding eachof the poor solvent (S1) and the solvent (S2), a single solvent alonecan be used or two or more solvents can be used in combination.

Examples of the base used in the step 3 include hydroxides of alkalimetals such as sodium hydroxide and potassium hydroxide; carbonates ofalkali metals such as sodium carbonate, potassium carbonate, and cesiumcarbonate; tertiary amines such as triethylamine and trimethylamine; andpyridine. Among the bases, preferred are potassium carbonate andtertiary amines and, in particular, more preferred are potassiumcarbonate and triethylamine because, after the reaction between thepolycondensate (A) and the (meth)acrylic acid halide (B), such bases canbe easily removed from the reaction system.

In the step 3, if necessary, a solvent may be used. Examples of thesolvent include monoalcohols such as methanol, ethanol, and propanol;polyols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol,1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol,1,8-octanediol, 1,9-nonanediol, trimethylene glycol, diethylene glycol,polyethylene glycol, and glycerin; glycol ethers such as2-ethoxyethanol, ethylene glycol monomethyl ether, ethylene glycolmonoethyl ether, ethylene glycol monopropyl ether, ethylene glycolmonobutyl ether, ethylene glycol monopentyl ether, ethylene glycoldimethyl ether, ethylene glycol ethyl methyl ether, and ethylene glycolmonophenyl ether; cyclic ethers such as 1,3-dioxane, 1,4-dioxane, andtetrahydrofuran; glycol esters such as ethylene glycol acetate; andketones such as acetone, methyl ethyl ketone, and methyl isobutylketone. These solvents may be used alone or in combination of two ormore thereof. Among these solvents, preferred are tetrahydrofuran,methyl ethyl ketone, and methyl isobutyl ketone because the compound tobe obtained is highly soluble therein.

In the step 3, the reaction temperature of the reaction between thepolycondensate (A) and the (meth)acrylic acid halide (B) is, forexample, 20° C. to 80° C. The reaction time is, for example, 1 to 30hours.

In the step 3, regarding the charging ratio of the polycondensate (A) tothe (meth)acrylic acid halide (B), a molar ratio [(A′)/(B)] where A′represents the number of moles of phenolic hydroxy groups of thepolycondensate (A) is preferably in the range of 1/1 to 1/3, morepreferably in the range of 1/1 to 1/2.5 because a radically curablecompound according to the present invention can be obtained with a highpurity and with a high yield.

A radically curable composition according to the present inventioncontains the above-described radically curable compound according to thepresent invention as an essential component. The radically curablecomposition may contain the above-described radically curable compoundaccording to the present invention alone or may further contain anotherradically curable compound.

Examples of the other radically curable compound used herein may includevarious epoxy (meth)acrylates and other (meth)acrylate compounds.

The epoxy (meth)acrylates may be obtained by, for example, subjectingvarious polyglycidyl ether compounds to an addition reaction with(meth)acrylic acid or a halide of (meth)acrylic acid. Examples of thevarious polyglycidyl ethers include polyglycidyl ethers of aromaticpolyols such as hydroquinone, 2-methylhydroquinone,1,4-benzenedimethanol, 3,3′-biphenol, 4,4′-biphenol,tetramethylbiphenol, biphenyl-3,3′-dimethanol, biphenyl-4,4′-dimethanol,bisphenol A, bisphenol B, bisphenol F, bisphenol S, 1,4-naphthalenediol,1,5-naphthalenediol, 1,6-naphthalenediol, 2,6-naphthalenediol,2,7-naphthalenediol, naphthalene-2,6-dimethanol, and4,4′,4″-methylidinetrisphenol;

polyglycidyl ethers of polyether-modified aromatic polyols obtained byring-opening polymerization between the above-described aromatic polyolsand various cyclic ether compounds such as ethylene oxide, propyleneoxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether,butyl glycidyl ether, phenyl glycidyl ether, or allyl glycidyl ether;

polyglycidyl ethers of lactone-modified aromatic polyols obtained bypolycondensation between the above-described aromatic polyols andlactone compounds such as ε-caprolactone;

polyglycidyl ethers of aromatic-ring-containing polyester polyolsobtained by a reaction between aliphatic dicarboxylic acids such asmalonic acid, succinic acid, glutaric acid, adipic acid, or pimelic acidand the above-described aromatic polyols;

polyglycidyl ethers of aromatic-ring-containing polyester polyolsobtained by a reaction between aromatic dicarboxylic acids or anhydridesthereof such as phthalic acid, phthalic anhydride, terephthalic acid,isophthalic acid, or orthophthalic acid, and aliphatic polyols such asaliphatic polyols such as ethylene glycol, diethylene glycol, propyleneglycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol,3-methyl-1,3-butanediol, 1,5-pentanediol, neopentyl glycol,1,6-hexanediol, trimethylolethane, trimethylolpropane, or glycerin;

bisphenol type epoxy resins such as bisphenol A type epoxy resins,bisphenol B type epoxy resins, bisphenol F type epoxy resins, andbisphenol S type epoxy resins; and

novolac type epoxy resins such as phenol novolac type epoxy resins andcresol novolac type epoxy resins. These resins may be used alone or incombination of two or more thereof.

Examples of the above-described other (meth)acrylate compounds includemonofunctional (meth)acrylate compounds such as n-butyl (meth)acrylate,isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl(meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl(meth)acrylate, 2-ethylhexyl (meth)acrylate, benzyl (meth)acrylate,phenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate,glycidyl (meth)acrylate, morpholine (meth)acrylate, 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl(meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycolmono(meth)acrylate, dipropylene glycol mono(meth)acrylate,2-methoxyethyl (meth)acrylate, methoxydiethylene glycol (meth)acrylate,methoxytriethylene glycol (meth)acrylate, methoxypolyethylene glycol(meth)acrylate, 2-butoxyethyl (meth)acrylate, butoxytriethylene glycol(meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-(2-ethoxyethoxyl)ethyl(meth)acrylate, ethoxypolyethylene glycol (meth)acrylate, 4-nonylphenoxyethylene glycol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate,caprolactone-modified tetrahydrofurfuryl (meth)acrylate, cyclohexyl(meth)acrylate, isobornyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl(meth)acrylate, cyclohexyl (meth)acrylate, cyclohexylmethyl(meth)acrylate, cyclohexylethyl (meth)acrylate, dicyclopentanyl(meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, dicyclopentenyl(meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, phenylbenzyl(meth)acrylate, and phenylphenoxyethyl acrylate;

di(meth)acrylate compounds such as ethylene glycol di(meth)acrylate,diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate,polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate,dipropylene glycol di(meth)acrylate, tripropylene glycoldi(meth)acrylate, butylene glycol di(meth)acrylate, tetrabutylene glycoldi(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanedioldi(meth)acrylate, 1,9-nonanediol di(meth)acrylate, neopentyl glycoldi(meth)acrylate, di(meth)acrylate of ethylene oxide adduct of bisphenolA, di(meth)acrylate of propylene oxide adduct of bisphenol A,di(meth)acrylate of ethylene oxide adduct of bisphenol F,di(meth)acrylate of propylene oxide adduct of bisphenol F,dicyclopentanyl di(meth)acrylate, glycerol di(meth)acrylate, neopentylglycol hydroxypivalic acid ester di(meth)acrylate, caprolactone-modifiedhydroxypivalic acid neopentyl glycol di(meth)acrylate,tetrabromobisphenol A di(meth)acrylate, hydropivalaldehyde-modifiedtrimethylolpropane di(meth)acrylate, 1,4-cyclohexanedimethanoldi(meth)acrylate, and bis[(meth)acryloylmethyl]biphenyl; and

(meth)acrylate compounds having a functionality of three or more such astrimethylolpropane tri(meth)acrylate, tri(meth)acrylate of ethyleneoxide adduct of trimethylolpropane, tri(meth)acrylate of propylene oxideadduct of trimethylolpropane, pentaerythritol tri(meth)acrylate,glycerol tri(meth)acrylate, tri(meth)acrylate of alkyl-modifieddipentaerythritol, ditrimethylolpropane tetra(meth)acrylate,tetra(meth)acrylate of ethylene oxide adduct of ditrimethylolpropane,tetra(meth)acrylate of propylene oxide adduct of ditrimethylolpropane,penta(meth)acrylate of dipentaerythritol, and hexa(meth)acrylate ofdipentaerythritol. These compounds may be used alone or in combinationof two or more thereof.

The radically curable composition contains the above-described radicallycurable compound according to the present invention in an amount as longas an advantage of the present invention, that is, high heat resistanceof cured products, is achieved. Specifically, a radically curablecompound according to the present invention is preferably used alone;or, with respect to 100 parts by mass of the total of a radicallycurable compound according to the present invention and anotherradically curable compound, the content of the radically curablecompound according to the present invention is preferably 50 parts bymass or more, more preferably 80 parts by mass or more.

A radically curable composition according to the present invention mayfurther contain a polymerization initiator and can be cured byirradiation with an active energy ray or by heating to thereby provide acured product.

In a case where a radically curable composition according to the presentinvention is cured through radical polymerization by irradiation with anactive energy ray, the polymerization initiator used is anintramolecular-cleavage-type photopolymerization initiator or ahydrogen-abstraction-type photopolymerization initiator.

Examples of the intramolecular-cleavage-type photopolymerizationinitiator include acetophenone-based compounds such as1-hydroxycyclohexyl phenyl ketone, diethoxyacetophenone,2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethylketal,1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one,4-(2-hydroxyethoxyl)phenyl-(2-hydroxy-2-propyl)ketone,2-methyl-2-morpholino(4-thiomethylphenyl)propan-1-one, and2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone; benzoins suchas benzoin, benzoin methyl ether, and benzoin isopropyl ether; acylphosphine oxide-based compounds such as2,4,6-trimethylbenzoindiphenylphosphine oxide andbis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide; azo compounds such as1,1′-azobisisobutyronitrile, 1,1′-azobiscyclohexanecarbonitrile, and2-cyano-2-propylazoformamide; benzil, and methyl phenylglyoxylate.

Examples of the hydrogen-abstraction-type photopolymerization initiatorinclude benzophenone-based compounds such as benzophenone, methylo-benzoylbenzoate-4-phenylbenzophenone, 4,4′-dichlorobenzophenone,hydroxybenzophenone, 4-benzoyl-4′-methyl-diphenylsulfide, acrylatedbenzophenone, 3,3′,4,4′-tetra(t-butylperoxycarbonyl)benzophenone, and3,3′-dimethyl-4-methoxybenzophenone; thioxanthone-based compounds suchas 2-isopropylthioxanthone, 2,4-dimethylthioxanthone,2,4-diethylthioxanthone, and 2,4-dichlorothioxanthone;aminobenzophenone-based compounds such as Michler's ketone and4,4′-diethylaminobenzophenone; 10-butyl-2-chloroacridone,2-ethylanthraquinone, 9,10-phenanthrenequinone, and camphorquinone.

Among the above-described photopolymerization initiators, preferred areacetophenone-based compounds such as 1-hydroxycyclohexyl phenyl ketone,2-hydroxy-2-methyl-1-phenylpropan-1-one,1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one,4-(2-hydroxyethoxyl)phenyl-(2-hydroxy-2-propyl)ketone,2-methyl-2-morpholino(4-thiomethylphenyl)propan-1-one, and2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone, andbenzophenone. In particular, 1-hydroxycyclohexyl phenyl ketone ispreferred. Such photopolymerization initiators may be used alone or incombination of two or more thereof.

The amount of such a photopolymerization initiator used with respect to100 parts by mass of a radically curable composition according to thepresent invention is preferably 0.01 to 20 parts by mass, morepreferably 0.1% to 15% by mass, still more preferably 0.5 to 10 parts bymass. Note that, in a case where an electron beam described below isused as an active energy ray, use of photopolymerization initiators isnot necessary.

Examples of an active energy ray used for curing a radically curablecomposition according to the present invention include ionizingradiations such as ultraviolet rays, electron beams, α-rays, β-rays, andγ-rays. Examples of energy sources or curing devices that generate suchactive energy rays include a germicidal lamp, an ultraviolet lamp (blacklight), carbon arc, a xenon lamp, a high-pressure mercury lamp forcopying, a medium- or high-pressure mercury lamp, an ultra-high-pressuremercury lamp, an electrodeless lamp, a metal halide lamp, ArF excimerlaser, an ultraviolet LED, ultraviolet rays from a light source such asnatural light, and electron beams from a scanning-type or curtain-typeelectron beam accelerator.

In a case where a radically curable composition according to the presentinvention is cured by thermal radical polymerization, a thermal radicalpolymerization initiator is used. Examples of the thermal radicalpolymerization initiator include organic peroxides such as benzoylperoxide, di-t-butyl peroxide, dicumyl peroxide, 3,3,5-trimethylhexanoylperoxide, di-2-ethylhexylperoxy dicarbonate, methyl ethyl ketoneperoxide, t-butyl peroxyphthalate, t-butyl peroxybenzoate, di-t-butylperoxyacetate, t-butyl peroxyisobutyrate, t-butyl peroxy-2-hexanoate,and t-butyl peroxy-3,3,5-trimethylhexanoate; and azo compounds such as1,1′-azobisisobutyronitrile, 1,1′-azobiscyclohexanecarbonitrile, and2-cyano-2-propylazoformamide. Among these thermal radical polymerizationinitiators, preferred are benzoyl peroxide and1,1′-azobisisobutyronitrile. These thermal radical polymerizationinitiators may be used alone or in combination of two or more thereof.

The amount of such a thermal radical polymerization initiator used withrespect to 100 parts by mass of a radically curable compositionaccording to the present invention is preferably 0.01 to 20 parts bymass, more preferably 0.1% to 15% by mass, still more preferably 0.5 to10 parts by mass.

EXAMPLES

Hereinafter, the present invention will be described further in detailwith reference to specific examples. Note that an NMR spectrummeasurement method used for identifying compounds is as follows.

[¹H-NMR Spectrum Measurement Method]

JNM-GSX500 (500 MHz, DMSO-d6, TMS) manufactured by JEOL Ltd. was used tocarry out a structural analysis.

Synthesis Example 1 Synthesis of Polycondensate (A-1)

To a 100-ml two-neck flask equipped with a condenser, 7.32 g (60 mmol)of 2,5-xylenol and 2.44 g (20 mmol) of 4-hydroxybenzaldehyde werecharged and dissolved in 20 ml of 2-ethoxyethanol. To this solutionbeing cooled in an ice bath, 2 ml of sulfuric acid was added. Theresultant solution was heated and stirred in an oil bath at 100° C. for2 hours to thereby cause a reaction. After the reaction, the resultantsolution was subjected to a reprecipitation process with water toprovide a crude product. The crude product was dissolved again inacetone and subjected to a reprecipitation process with water. Theresultant product was isolated by filtration and subjected to vacuumdrying. This provided 5.93 g of a polycondensate (A-1) having amolecular structure represented by a formula (5-1) below. The purity ofthe polycondensate (A-1) in the crude product was 87% by mass on thebasis of GPC area ratio. The purity of the polycondensate (A-1) finallyobtained was 99% by mass.

Example 1 Synthesis of Radically Curable Compound

To a 100-ml two-neck flask equipped with a condenser, 1.74 g (5 mmol) ofthe polycondensate (A-1), 4.10 g (30 mmol) of potassium carbonate, and10 ml of tetrahydrofuran were charged and stirring was initiated. Tothis solution being cooled in an ice bath, 3.60 g (20 mmol) of acryloylchloride was added dropwise over 30 minutes. The resultant solution washeated and stirred in an oil bath at 70° C. for 12 hours to therebycause a reaction. After the reaction, solid content was separated fromthe resultant solution by filtration; the filtrate was mixed with 30 mlof chloroform and washed three times with 50 ml of water. The underlyingorganic layer was separated and dried over sodium sulfate. After that,the solvent was distilled off under a reduced pressure to provide 1.79 gof a radically curable compound (1) that was white acicular crystals.This compound was identified on the basis of peaks of 1H-NMR and it wasconfirmed that the compound represented by a structural formula (3-1)was obtained at a purity of 100%. FIG. 1 is the chart of the ¹H-NMRspectrum.

The spectral peak values of the ¹H-NMR spectrum are as follows.

[¹H-NMR Spectrum]

(ppm, 500 MHz, solvent: DMSO-d₆, standard: TMS)

1.9-2.2 (12H; Ar—CH₃ ), 5.6-5.8 (1H; Ar—CH), 6.1-6.3 (3H; C-CH₂ ),6.4-6.5 (3H; CO—CH—C), 6.5-6.6 (2H; Ar), 6.6-6.7 (3H; C—CH₂ ), 6.9-7.3(6H; Ar)

Comparative Synthesis Example 1 Synthesis of Bisphenol A (BPA) TypeEpoxy Acrylate

A reaction between 188 parts by mass of a bisphenol A (BPA) type liquidepoxy resin (“EPICLON850” manufactured by DIC Corporation; epoxyequivalent weight: 188 g/eq.) and 72% by mass of acrylic acid (in aratio so as to satisfy number of epoxy groups:total number of carboxylgroups=1:1) was caused at 95° C. to provide 253 parts by mass of a BPAtype epoxy acrylate that was a transparent viscous liquid.

Comparative Synthesis Example 2 Synthesis of Tetramethylbiphenyl TypeEpoxy Acrylate

A reaction between 195 parts by mass of a tetramethylbiphenyl typeliquid epoxy resin (“JER YX-4000H” manufactured by Mitsubishi ChemicalCorporation; epoxy equivalent weight: 195 g/eq.) and 72 parts by mass ofacrylic acid (in a ratio so as to satisfy number of epoxy groups:totalnumber of carboxyl groups=1:1) was caused at 95° C. to provide 264 partsby mass of a tetramethylbiphenyl type epoxy acrylate that was atransparent viscous liquid.

Comparative Synthesis Example 3 Synthesis of Cresol Novolac Type EpoxyAcrylate

A reaction between 214 parts by mass of an o-cresol novolac type epoxyresin (“EPICLON N-695” manufactured by DIC Corporation; epoxy equivalentweight: 214 g/eq.) and 72 parts by mass of acrylic acid (in a ratio soas to satisfy number of epoxy groups:total number of carboxylgroups=1:1) was caused at 100° C. to provide 273 parts by mass of acresol novolac type epoxy acrylate that was a yellow solid.

Test Examples 1 and 2 and Comparative Test Examples 1 to 6

The acrylates obtained in Example 1 and Comparative synthesis examples 1to 3 above were used to prepare cured products in Test examples 1 and 2and Comparative test examples 1 to 6. The glass transition temperatureof each cured product was measured and the heat resistance of the curedproduct was evaluated by a method described below. The results aredescribed in Table 1.

Test Example 1

The radically curable compound (1) (0.50 g) obtained in Example 1, 0.05g of IRGACURE 184 [manufactured by Ciba Specialty Chemicals], and 0.5 gof tetrahydrofuran were placed into a Schlenk tube and subjected tofreeze-drying in a nitrogen atmosphere. This reaction vessel was sealedand irradiated for 3 hours with light from a high-pressure mercury lampequipped with a 340 nm band-pass filter. The resultant content wassubjected to a reprecipitation process with methanol. The resultantprecipitate was subjected to filtration and vacuum drying to provide0.35 g of a polymer (a). The obtained polymer (a) was subjected to a DSCmeasurement to perform evaluation in terms of heat resistance (Tg).

Test Example 2

The radically curable compound (1) (0.50 g) obtained in Example 1, 0.05g of azobisisobutyronitrile [AIBN; reagent manufactured by Wako PureChemical Industries, Ltd.], and 0.5 g of dichloroethane were placed intoa Schlenk tube and subjected to freeze-drying in a nitrogen atmosphere.This reaction vessel was sealed and a reaction was caused at 70° C. for12 hours. The resultant content was subjected to a reprecipitationprocess with methanol. The resultant precipitate was subjected tofiltration and vacuum drying to provide 0.21 g of a polymer (b). Theobtained polymer (b) was subjected to a DSC measurement to performevaluation in terms of heat resistance (Tg).

Comparative Example 1

The same processes were performed as in Example 2 except that theradically curable compound (1) in Example 2 was replaced by the BPA typeepoxy acrylate obtained in Comparative synthesis example 1. Thus, 0.23 gof a cured product of the BPA type epoxy acrylate was obtained. As inTest example 1, evaluation in terms of heat resistance (Tg) wasperformed.

Comparative Example 2

The same processes were performed as in Example 3 except that theradically curable compound (1) in Example 3 was replaced by the BPA typeepoxy acrylate obtained in Comparative synthesis example 1. Thus, 0.13 gof a cured product of the BPA type epoxy acrylate was obtained. As inTest example 1, evaluation in terms of heat resistance (Tg) wasperformed.

Comparative Example 3

The same processes were performed as in Example 2 except that theradically curable compound (1) in Example 2 was replaced by thetetramethylbiphenyl type epoxy acrylate obtained in Comparativesynthesis example 2. Thus, 0.35 g of a cured product of thetetramethylbiphenyl type epoxy acrylate was obtained. As in Test example1, evaluation in terms of heat resistance (Tg) was performed.

Comparative Example 4

The same processes were performed as in Example 3 except that theradically curable compound (1) in Example 3 was replaced by thetetramethylbiphenyl type epoxy acrylate obtained in Comparativesynthesis example 2. Thus, 0.33 g of a cured product of thetetramethylbiphenyl type epoxy acrylate was obtained. As in Test example1, evaluation in terms of heat resistance (Tg) was performed.

Comparative Example 5

The same processes were performed as in Example 2 except that theradically curable compound (1) in Example 2 was replaced by the cresolnovolac type epoxy acrylate obtained in Comparative synthesis example 3.Thus, 0.37 g of a cured product of the cresol novolac type epoxyacrylate was obtained. As in Test example 1, evaluation in terms of heatresistance (Tg) was performed.

Comparative Example 6

The same processes were performed as in Example 3 except that theradically curable compound (1) in Example 3 was replaced by the cresolnovolac type epoxy acrylate obtained in Comparative synthesis example 3.Thus, 0.42 g of a cured product of the cresol novolac type epoxyacrylate was obtained. As in Test example 1, evaluation in terms of heatresistance (Tg) was performed.

[Method of Measuring Glass Transition Temperature of Cured Product]

A differential scanning calorimeter (“differential scanning calorimeter(DSC) Q100” manufactured by TA Instruments) was used to measure a glasstransition temperature (hereafter abbreviated as “Tg”) in a nitrogenatmosphere in a temperature range of 25° C. to 450° C. at a temperatureincrease rate of 10° C./min.

[Evaluation of Cured Product in Terms of Heat Resistance]

On the basis of Tg temperatures determined in the above-describedmeasurements, evaluation in terms of heat resistance was performed inaccordance with the following criteria.

Excellent: Tg is 300° C. or more

Good: Tg is 250° C. or more and less than 300° C.

Fair: Tg is 200° C. or more and less than 250° C.

Poor: Tg is less than 200° C.

Table 1 summarizes the raw materials cured into the cured products inExamples 2 and 3 and Comparative examples 1 to 6 above and results of Tgvalues and heat resistance evaluation. Note that “>400” of Tg ofExamples 2 and 3 means that thermal decomposition occurs at atemperature higher than 400° C. without observation of glass transitiontemperature.

TABLE 1 Test Test Comparative Comparative Comparative ComparativeComparative Comparative example example test test test test test test 12 example 1 example 2 example 3 example 4 example 5 example 6 ComponentsRadically curable 0.5 0.5 (g) compound BPA type epoxy acrylate 0.5 0.5Tetramethylbiphenyl 0.5 0.5 type epoxy acrylate Cresol novolac type 0.50.5 epoxy acrylate IRGACURE 184 0.05 0.05 0.05 0.05 AIBN 0.01 0.01 0.010.01 Curing method Photo Thermal Photo Thermal Photo Thermal PhotoThermal curing curing curing curing curing curing curing curingEvaluation Tg (° C.) >400 >400 158 163 171 178 221 229 results Heatresistance Excellent Excellent Poor Poor Poor Poor Fair Fair

The results in Table 1 indicate the following: the cured products (Testexamples 1 and 2) of the radically curable compound according to thepresent invention obtained in Example 1 thermally decompose attemperatures higher than 400° C. without observation of glass transitiontemperature and hence have very high heat resistance.

On the other hand, the cured products of existing epoxy acrylates thathave been considered to have high heat resistance in Comparativeexamples 1 to 6 have Tg of 158° C. to 229° C., which are inferior to interms of heat resistance the cured products of the radically curablecompound according to the present invention.

The invention claimed is:
 1. A radically curable compound represented bya general formula (1) below

where R¹, R², and R³ each independently represent an alkyl group having1 to 8 carbon atoms; m and n each independently represent an integer of1 to 4; p represents an integer of 0 to 4; X, Y, and Z eachindependently represent an acryloyloxy group or a methacryloyloxy group;and t represents 1 or
 2. 2. A radically curable compound represented bya general formula (2) below

where R¹, R², and R³ each independently represent an alkyl group having1 to 8 carbon atoms; m and n each independently represent an integer of1 to 4; p represents an integer of 0 to 4; and X, Y, and Z eachindependently represent an acryloyloxy group, a methacryloyloxy group,or a hydroxy group, and at least one of X, Y, and Z represents anacryloyloxy group or a methacryloyloxy group; and t represents 1 or 2,wherein at least one hydroxyl group is not in the ortho-position withrespect to the center.
 3. The radically curable compound according toclaim 1, wherein R¹, R², and R³ above each represent a methyl group. 4.A radically curable compound represented by a general formula (1) below

where R¹, R², and R³ each independently represent an alkyl group having1 to 8 carbon atoms; m, n, and p each independently represent an integerof 1 to 3; X, Y, and Z each independently represent an acryloyloxygroup, a methacryloyloxy group, or a hydroxy group, and at least one ofX, Y, and Z represents an acryloyloxy group or a methacryloyloxy group;and t represents 1 or 2, wherein at least one hydroxyl group is not inthe ortho-position with respect to the center.
 5. A radically curablecomposition comprising the radically curable compound according toclaim
 1. 6. A cured product obtained by curing the radically curablecomposition according to claim 5 with an active energy ray or heat.
 7. Aresist-material composition comprising the radically curable compositionaccording to claim
 5. 8. A radically curable composition comprising theradically curable compound according to claim
 2. 9. A radically curablecomposition comprising the radically curable compound according to claim3.
 10. A radically curable composition comprising the radically curablecompound according to claim
 4. 11. A cured product obtained by curingthe radically curable composition according to claim 8 with an activeenergy ray or heat.
 12. A radically curable compound represented by ageneral formula (1) below

where R¹, R², and R³ each independently represent an alkyl group having1 to 8 carbon atoms; m and n each independently represent an integer of1 to 4; p represents an integer of 0 to 4; X, Y, and Z eachindependently represent an acryloyloxy group, a methacryloyloxy group,or a hydroxy group, and only one of X, Y, and Z represents a hydroxygroup; and t represents 1 or 2, wherein the hydroxyl group is not in theortho-position with respect to the center.
 13. The radically curablecompound according to claim 2, wherein R¹, R², and R³ above eachrepresent a methyl group.
 14. The radically curable compound accordingto claim 4, wherein R¹, R², and R³ above each represent a methyl group.15. The radically curable compound according to claim 12, wherein R¹,R², and R³ above each represent a methyl group.
 16. A radically curablecomposition comprising the radically curable compound according to claim12.
 17. A resist-material composition comprising the radically curablecomposition according to claim
 8. 18. A resist-material compositioncomprising the radically curable composition according to claim
 10. 19.A resist-material composition comprising the radically curablecomposition according to claim
 13. 20. A resist-material compositioncomprising the radically curable composition according to claim 14.